What would you do

So my husbands boss (who is also my soon to be sister in laws maid of honour) just broke up with her long term boyfriend as she was caught cheating during a wedding dress shopping trip. Apparently she’s been cheating for a while and she likes to get around. Anyway it seems like she is trying to hook up with guys at work and I’m worried she will make a move on my husband. I’m not worried about him doing anything I know he won’t but I’m worried that she might punish him in some way for not doing anything like cutting his hours or giving him really labour taxing jobs. What would you do? And is there anything I can actually do? Also I’m not meant to know about her cheating as it told to someone in confidence who told me worried about the same.